I had a similar probem with .458 premium bullets that just wouldn't feed in my new .458 lott. Very disappointing. Thing was, it was a Ruger, not a CZ. No problem with the rifle - it was a problem with that particular bullet design (since fixed by that manufacturer). Lots of other really good loads did work.
For all the things that don't work, there's usually a lot of good solutions that do.
Dan
